Pressure measuring arrangement

ABSTRACT

The invention relates to a pressure measuring arrangement comprising a pressure measuring cell ( 5 ) which is fed by a pressure corresponding to the pressure which is to be measured by a pressure tube ( 3 ) filled by a pressurised liquid; at least one pressure recording unit ( 25, 45 ) is arranged separately from said cell, said unit being impinged upon by a pressure which is to be measured during operation, producing a pressure corresponding to the pressure which is to be measured via a pressure line ( 33, 55 ) filled by a liquid; a connection between the pressure tube ( 3 ) and the pressure line ( 33, 55 ). A modular design and a large amount of flexibility is obtained in respect of the spatial arrangement of the pressure measuring cell ( 5 ) and the pressure recording unit ( 25, 45 ). The connection consists of a base body ( 27, 57, 59, 61, 62, 77, 79 ) wherein at least one end section of the pressure line ( 33, 55 ) is arranged, in addition to a pressure screw ( 35, 65 ) through which the pressure tube ( 3 ) passes and is secured by a fixing element arranged on a side which is oriented towards the base body of the pressure screw ( 35, 65 ). Said pressure screw has a thread which enables it to be screwed onto base body ( 27, 57, 59, 61, 62, 77, 79 ) in such a way that the pressure tube ( 3 ) and the pressure line ( 33, 55 ) are connected, and the connection is effectively sealed between the pressure tube ( 3 ) and the pressure line ( 33, 55 ).

[0001] The invention relates to a pressure measuring arrangement with apressure measuring cell and a pressure recording unit, in which inoperation a pressure to be measured acts on the pressure recording unitand is converted into a pressure corresponding to the pressure to bemeasured, which converted pressure is delivered via a fluid-filledconnection from the pressure recorder to the pressure measuring cell ofthe pressure measuring cell.

[0002] Such pressure measuring arrangements are used if a pressure to bemeasured cannot be delivered directly to the pressure measuring cell.This is the case for instance whenever the pressure measuring cell isvery vulnerable to chemical and/or mechanical stresses, as is the casefor instance with piezoresistive pressure measuring cells that forinstance have measuring membranes comprising or having vulnerablesemiconductor components, or if a difference between two pressures thatact at different locations is to be detected with a measuring cellembodied as a differential-pressure measuring cell. Such pressuremeasuring arrangements are also used if a ceramic pressure measuringcell is to be used and if, for instance for hygienic reasons, a flushclosure off from the process at the front is desired. These pressuremeasuring arrangements must be filled, once their manufacture isconcluded, with a fluid that transmits the pressure corresponding to thepressure to be measured. To that end, the measuring arrangement isevacuated, for instance, and placed in a bath with the fluid andflooded. The fill openings are then closed, and the measuringarrangement can be connected to a site where it will be used.

[0003] Since the filling is comparatively complicated and requiresspecial operating media, a measuring arrangement once completed is as arule no longer changed.

[0004] For the sake of great flexibility with a view to measuringarrangements that can be furnished quickly, examples being variouspossible combinations of different pressure measuring cells withdifferent pressure measurement recorders, or different oil supplies orpressure lines of different lengths, without having to keep all possiblevariants of pressure measuring arrangements on hand in adequate numbers,it is therefore desirable for such a pressure measuring arrangement tobe embodied in modular fashion and then put together and filled asneeded.

[0005] U.S. Pat. No. 4,833,922 describes a differential-pressuremeasuring cell of nodular construction, having

[0006] a pressure measuring cell,

[0007] to which a pressure corresponding to a pressure to be measured isdelivered via a fluid-filled pressure tube;

[0008] at least one pressure recording unit,

[0009] on which in operation a pressure to be measured acts, and

[0010] which makes a pressure corresponding to the pressure to bemeasured available via a fluid-filled pressure line; and

[0011] a connection between the pressure tube and the pressure line.

[0012] The differential-pressure measuring cell is very compactlydesigned. To that end, the pressure measuring cell is disposed directlyin the pressure recording unit, and the pressure tubes are introducedinto bores of the pressure recorder that form pressure lines.Frustoconical sealing elements are provided, which annularly surroundthe pressure tubes and are introduced into recesses of the same shape inthe pressure recorder. A fastening is provided that presses the sealingelements inward into the recesses of the same shape. The fasteningsurrounds the pressure tubes annularly and is screwed onto the pressurerecorded, for instance by means of tension bolts.

[0013] Such a compact design is not always usable. For instance, spaceconditions at the usage site, high temperatures acting on the pressurerecorder, or pressure measuring cells that require a special mode ofinstallation, for instance in a manner that is as free from fastening aspossible, necessitate a spatial separation of the pressure measuringcell and the pressure recorder.

[0014] It is an object of the invention to disclose a pressure measuringarrangement which is of modular construction and has a high degree offlexibility in terms of the three-dimensional disposition of thepressure measuring cell and the pressure recorder relative to oneanother.

[0015] To this end, the invention comprises a pressure measuringarrangement, having

[0016] a pressure measuring cell,

[0017] to which a pressure corresponding to a pressure to be measured isdelivered via a fluid-filled pressure tube;

[0018] at least one pressure recording unit disposed separatelytherefrom,

[0019] on which in operation a pressure to be measured acts, and

[0020] which makes a pressure corresponding to the pressure to bemeasured available via a fluid-filled pressure line; and

[0021] a connection between the pressure tube and the pressure line,which connection includes:

[0022] a base body, in which at least one end portion of the pressureline is disposed,

[0023] a pressure screw,

[0024] through which screw the pressure tube is passed and is securedthere by means of a mount disposed on a side of the pressure screworiented toward the base body, and

[0025] which screw has a thread by means of which it is screwed onto thebase body, in such a way that

[0026] the pressure tube and the pressure line communicate, and

[0027] sealing of the connection between the pressure tube and thepressure line is effective.

[0028] The invention also comprises a pressure measuring arrangement,having

[0029] a pressure measuring cell,

[0030] to which a pressure corresponding to a pressure to be measured isdelivered via a fluid-filled pressure tube;

[0031] at least one pressure recording unit disposed separatelytherefrom,

[0032] on which in operation a pressure to be measured acts, and

[0033] which makes a pressure corresponding to the pressure to bemeasured available via a fluid-filled pressure line; and

[0034] a connection between the pressure tube and the pressure line,which connection includes:

[0035] a base body, in which at least one end portion of the pressureline is disposed,

[0036] a pressure screw,

[0037] through which screw the pressure line is passed and is securedthere by means of a mount disposed on a side of the pressure screworiented toward the base body, and

[0038] which screw has a thread by means of which it is screwed onto thebase body, in such a way that

[0039] the pressure tube and the pressure line communicate, and

[0040] sealing of the connection between the pressure tube and thepressure line is effective.

[0041] In a first embodiment, the thread is a male thread, which isscrewed into a recess in the base body. The pressure line or thepressure tube leads to the recess, and the mount is a ring mechanicallysolidly connected to the pressure tube or to the pressure line, which inthe mounted state rests sealingly, with an end face oriented toward thepressure screw, on an end face of the pressure screw oriented toward thebase body.

[0042] In a further feature, the pressure tube tapers conically on theoutward end, and rests sealingly on a conical inside face of the sameshape in the region of the orifice of the pressure line.

[0043] In a second embodiment, the pressure screw is a union nut, whichtakes the form of a cylinder closed on one end by a radiallyinward-extending shoulder. The cylinder has a female thread, which isscrewed onto a male thread of the base body; and the pressure tube ispassed through the shoulder into the pressure screw.

[0044] In a first feature of the second embodiment, the pressure linedischarges into the base body and is connected tightly and mechanicallysolidly to it; the pressure tube is connected tightly and mechanicallysolidly to an annular disk coaxially surrounding the pressure tube; anend face of the annular disk rests on an annular-disklike inside face ofthe shoulder; and the annular disk is pressed by the pressure screw inthe direction toward the base body.

[0045] In a feature of this last embodiment, between the annular diskand the base body, a sealing element annularly surrounding the pressuretube is provided, by which a hollow chamber, defined by the annulardisk, the sealing element, and the base body, and surrounding thepressure tube is sealed off.

[0046] In a second feature of the second embodiment, the pressure tubeis widened by crimping in the interior of the is pressure screw; thepressure line is introduced into the pressure tube; the pressure line ispassed through the base body and mechanically solidly connected to it;the pressure line tapers conically on the outward end; and a crimped-onend portion of the pressure tube is fastened sealingly between a conicaljacket face, disposed in the interior of the pressure screw, and theconical portion of the pressure line, in that the jacket face is pressedagainst the pressure line by the pressure screw in the direction towardthe base body.

[0047] In a third feature of the second embodiment, a clamping cone isdisposed on the end in the pressure screw, which clamping cone has anouter jacket face that tapers conically in the direction toward the basebody, which jacket face grips the pressure tube and in which thepressure tube is fastened, in that the clamping cone is pressed inwardwith its conical jacket face by the pressure screw into an inner jacketface of the base body that is oriented toward the clamping cone andtapers conically in the direction remote from the clamping cone.

[0048] In a further feature of this last embodiment, on an end of thebase body opposite the pressure screw, a second pressure screw ofidentical form is provided, through the pressure line is introduced intoa bore penetrating the base body, in which bore a second clamping coneis disposed on the end, which clamping cone has an outer jacket facetapering conically in the direction toward the base body, which jacketface grips the pressure line and in which the pressure line is fastened,in that the second clamping cone is pressed inward with its conicaljacket face by the second pressure screw into an inner jacket face ofthe base body oriented toward the second clamping cone and taperingconically in the direction remote from the clamping cone.

[0049] The invention and further advantages will now be described infurther detail in conjunction with the drawings, in which sevenexemplary embodiments are shown. Identical elements are identified inthe drawings by the same reference numerals.

[0050]FIG. 1 shows a section through a pressure measuring arrangement ofthe invention, in which a pressure measuring cell is disposed in ahousing disposed separately from a pressure recorder, and a pressuretube on the pressure recorder communicates with a pressure line of thepressure recorder;

[0051]FIG. 2 shows a section through a pressure measuring arrangement ofthe invention, in which a pressure measuring cell is disposed in ahousing disposed separately from a pressure recorder, and a pressureline on the housing communicates with a pressure tube of the pressuremeasuring arrangement;

[0052]FIG. 3 shows a section through a connection according to theinvention between a pressure tube and a pressure line, which is spacedapart from the pressure recorder and from the pressure measuring cell;

[0053]FIG. 4 shows a section through a further connection according tothe invention between a pressure tube and a pressure line, which isspaced apart from the pressure recorder and from the pressure measuringcell;

[0054]FIG. 5 shows a section through a further exemplary embodiment of aconnection according to the invention between a pressure tube and apressure line, in which a portion of the pressure tube crimped on at theend is used to fix the pressure tube, and sealing is effected by meansof conically embodied jacket faces of the pressure tube and pressureline;

[0055]FIG. 6 shows a section through a clamping cone connection betweena pressure line and a pressure tube; and

[0056]FIG. 7 shows a section through a connection between a pressureline and a pressure tube, in which the pressure line and the pressuretube are each connected to a base body by means of a respective clampingcone connection.

[0057]FIG. 1 shows a section through a pressure measuring arrangement ofthe invention. It has a capacitive ceramic pressure measuring cell, inthis case a relative-pressure measuring cell, that is soldered onto apressure tube 3 in a manner free from fastening in a housing 1.

[0058] The pressure measuring cell 5 includes two ceramic base bodies 7,between which a membrane 9 is disposed. The membrane 9 is connected bymeans of two annular joining points 11 to the base bodies 7, forming afirst and a second chamber 13, 15. The first chamber 13 communicateswith the pressure tube 3 via a bore in the base body 7. In the exemplaryembodiment shown, the pressure tube 3 is soldered into the bore in thebase body 7. By way of the pressure tube 3, the pressure measuring cell5 is supplied with a pressure corresponding to a pressure to bemeasured.

[0059] To that end, the first chamber 13 and the pressure tube 3 arefilled with a substantially incompressible fluid, such as a siliconeoil, that is acted upon by that pressure.

[0060] The second chamber 15 is opened relative to an interior of thehousing 1 of the pressure measuring cell 5 via a bore 17 that passescontinuously through the base body adjoining this second chamber. Adeflection of the membrane 9 is thus dependent on the pressurecorresponding to the pressure to be measured, which is referred to theambient pressure operative in the interior of the housing. Thedeflection of the membrane is detected by a capacitor, which is disposedin the first chamber 13 and which has both a measuring electrode 19,disposed on a bottom face of the base body 7 toward the membrane, and acounter-electrode 21 applied to the membrane 9 facing the measuringelectrode. The measuring electrode 19, for detecting the instantaneouscapacitance, is connected via a through-connection through the base body7 to an electronic circuit 23, which converts the capacitance into anelectrical output signal and makes it available for further processingand/or evaluation via connecting lines.

[0061] At least one pressure recording unit 25 is disposed separatelyfrom the housing 1 and from the pressure measuring cell 5. In theexemplary embodiment shown, only one pressure recording unit 25 isprovided. If instead of the relative-pressure measuring cell shown adifferential-pressure measuring cell were provided, then it would beunderstood that there would be two pressure recording units, eachconnected to one pressure tube via a respective pressure line. Adifferential-pressure measuring cell of this kind could for instance beconstructed similarly to the ceramic relative-pressure measuring celldescribed. From the relative-pressure measuring cell described, adifferential-pressure measuring cell is obtained by introducing a secondpressure tube into the open bore, shown in FIG. 1, of the second chamber15, which second pressure tube is connected to a second pressure line ofa second pressure recorder. The pressure transmission from the secondpressure recorder into the associated chamber is effected via a fluid,with which the pressure recorder, the second pressure line, the secondpressure tube, and the chamber are filled.

[0062] The pressure recording unit 25 shown in FIG. 1 has a base body 27and a partitioning membrane 31, secured on the front, enclosing achamber 29, to it by its outer edge. In operation, the pressure to bemeasured acts on the partitioning membrane 31 of the pressure recordingunit 25. The base body 27 and the partitioning membrane 31 comprise ametal, such as a special steel.

[0063] The base body 27 has a continuous bore, one end of whichdischarges into the chamber 29. The bore forms a pressure line 33 and,just like the chamber 29, is filled with a substantially incompressiblefluid, such as a silicone oil. A pressure to be measured, which inoperation is exerted on the outside of the partitioning membrane 31, isconverted in the chamber 29 into a pressure corresponding to it; thefluid is at this latter pressure and that pressure is available via thefluid-filled pressure line 33.

[0064] A connection is provided between the pressure tube 3 and thepressure line 33. The connection includes the base body 27, in which atleast an end portion of the pressure line 33 is disposed. In theexemplary embodiment shown, the entire pressure line 33 is disposed inthe base body 27.

[0065] The connection further includes a pressure screw 35, throughwhich the pressure tube 3 is passed. On a side of the pressure screw 35toward the base body, a mount 39 is provided, by which the pressure tube3 is secured. In the exemplary embodiment shown, the mount 39 is a ring,which is mechanically solidly connected to the pressure tube 3 and whichin the mounted state rests, with an end face toward the pressure screw35, on an end face of the pressure screw 35 oriented toward the basebody. In the exemplary embodiment shown, the mechanical fastening isrealized by a male thread, formed onto the pressure tube 3, onto whichthe mount 39 is screwed. The position of the male thread determines howfar the pressure tube 3 protrudes out of the pressure screw 35 and outof the mount 39. It is understood that still other mechanically solidconnections that prevent a motion of the pressure tube 3 in thedirection remote from the base body can also be used. For instance, thepressure tube 3 can be soldered into the mount 39 or welded there.

[0066] The pressure screw 35 has a thread 37, by means of which it isscrewed into the base body 27 in such a way that the pressure tube 3 andthe pressure line 33 are in communication, and sealing between thepressure tube 3 and the pressure line 33 is effective.

[0067] In the exemplary embodiment shown in FIG. 1, the thread 37 is amale thread, which is screwed into a cylindrical recess 41 in the basebody 27. If the pressure screw 35 has a clockwise thread, then the mount39 is preferable secured with a counterclockwise thread, to precludeloosening of the mount 39 when the pressure screw 35 is being screwedin.

[0068] The pressure tube 3 comprises a metal, such as a special steel.The mount 39 preferably likewise comprises a metal. The pressure line 33leads to the recess 41 and discharges there. The pressure tube 3 tapersconically on the outward end and rests sealingly on a conical insideface 43, of the same shape, of the base body 27 in the region of theorifice of the pressure line 33. The mount 39 is thus located in theinterior of the recess 41, and the pressure tube 3 is pressed againstthe orifice of the pressure line 33 as a result of the screwing in ofthe pressure screw 35 and the resultant force exerted on the mount 39 inthe direction toward the base body, so that the sealing of theconnection between the pressure tube 3 and the pressure line 33 by theconical jacket faces pressed against one another is effective.

[0069]FIG. 2 shows an exemplary embodiment that substantially agreeswith the exemplary embodiment shown in FIG. 1. Unlike the exemplaryembodiment shown in FIG. 1, however, the connection is not made directlyat the pressure recorder 45 but instead near the pressure measuring cell5. For that purpose, the housing 1 in the region of the exit point ofthe pressure line 4 has a base body 28 formed onto it. The pressure tube4 is soldered into a bore that penetrates the base body 28 anddischarges there. Hence at least one end portion of the pressure tube 4is disposed in the base body 28. Analogously to the exemplary embodimentshown in FIG. 1, the base body 28 has a recess 41, into which thepressure screw 35 is screwed. A pressure line 34 is provided, whichleads from the pressure recorder 25 to the base body 28, where itprotrudes through the pressure screw 35 into the recess 41. Just as inthe exemplary embodiment shown in FIG. 1, an identically embodied mount39 is provided here in the interior of the recess 41, and this mountsecures the pressure line 34.

[0070] The sealing of the connection between the pressure line 34 andthe pressure tube 4 is effected by providing the pressure line 34 with aconical outer jacket face on its end, which face is pressed into therecess 41 by the screwing in of the pressure screw 35 against an innerjacket face 44, of the same shape, of the base body 28 in the region ofthe orifice of the bore.

[0071] The pressure recorder 45 has a base body 47 and a partitioningmembrane 49 and is embodied similarly to the pressure recorder shown inFIG. 1. The base body 47 has a continuous bore 51, which discharges intoa chamber 53 enclosed between the base body 47 and the partitioningmembrane 49. The pressure line 34 is welded or soldered into an end ofthe bore 51 remote from the chamber.

[0072]FIG. 3 shows a further exemplary embodiment, which is similar toboth of the exemplary embodiments described above. A housing, not shownin FIG. 3, and a pressure measuring cell, also not shown, are, like thepressure line 3, are embodied similarly to the corresponding componentsin FIG. 1, and the pressure recorder 45 corresponds to that shown inFIG. 2. A pressure line 55 is welded or soldered into the bore 51 of thepressure recorder 45.

[0073] The pressure line 55 communicates with the pressure tube 3 thatleads to the pressure measuring cell 5, not shown in FIG. 3. Aconnection spaced apart from the pressure recorder 45 and from thepressure measuring cell 5 exists between the pressure tube 3 and thepressure line 55, and it has a base body 57 in which an end portion ofthe pressure line 55 is disposed. The pressure line 55 and the base body57 comprise a metal, such as a special steel. The base body 57 has acontinuous bore, into which the pressure line 55 is for instance welded.

[0074] The connection of the pressure line 55 and the pressure tube 3 iseffected analogously to the exemplary embodiment shown in FIG. 1, bymeans of a pressure screw 35, screwed into the recess 41 in the basebody 57, and by means of a mount 39 and a conical jacket face of thepressure tube 3, which face is pressed by the pressure screw 35 againstan identically shaped conical jacket face of the base body 57 in theregion of the orifice of the pressure line 55, and so this connection istherefore not described again here.

[0075] In FIGS. 4 and 5, two further embodiments of connections, spacedapart from the pressure recorder and from the pressure measuring cell,between the pressure tube 3 and the pressure line 55 are shown. Thepressure measuring cell 5 connected to the pressure tube 3 and thepressure recorder 25 connected to the pressure line 55 are not shown inFIGS. 4 and 5. Examples of them can be taken identically from FIGS. 1and 2.

[0076] In the embodiments shown in FIGS. 4 and 5, the connection in eachcase includes a respective essentially cylindrical base body 59, 62,with a central axial bore into which the pressure line 55 is introducedand is connected tightly and mechanically solidly by means of a solderedconnection 63.

[0077] In each case, a pressure screw 65 is provided that coaxiallysurrounds the pressure tube 3. The pressure screws 65 are union nuts,which take the form of a cylinder closed at one end by a radiallyinward-extending shoulder 67. The cylinders have a female thread, whichis screwed onto a male thread of the base body 59, 62. The pressuretubes 3 are passed through the shoulder 67 on into the union nut andsecured by means of a mount disposed on a side, toward the base body, ofthe pressure screw 65.

[0078] The union nuts are screwed onto the base bodies 59, 62 in such away that the pressure tube 3 and the pressure line 55 are incommunication, and sealing of the connection between the pressure tube 3and the pressure line 55 is effective. In the exemplary embodiment shownin FIG. 4, the mount comprises an annular disk 69, which coaxiallysurrounds the pressure tube 3 and is connected to it tightly andmechanically solidly, for instance by means of a soldered connection 71.The annular disk 69 is disposed inside the pressure screw 65 and restswith one end face on an annular-disklike inside face of the shoulder 67.The annular disk 69 is pressed against the base body 59 by the pressurescrew 65.

[0079] The pressure tube 3 is introduced through the mount into the basebody 59. The sealing of the connection is effected by a sealing element73, disposed between the annular disk 69 and the base body 59 andannularly surrounding the pressure tube 3. By means of the sealingelement 73, a hollow chamber, which is defined by the annular disk 69,sealing element 73 and base body 59, and which encloses the connectionbetween the pressure tube 3 and the pressure line 55, is sealed off. Thesealing element 73 in this exemplary embodiment is a ring of oval crosssection, which rests on a conical end face of the base body 59. Otherseal geometries are equally usable. It comprises a metal, such ascopper. The pressure screw 65 and the base body 59 likewise comprise ametal, such as a special steel.

[0080] In the exemplary embodiment shown in FIG. 5, the pressure tube 3is widened by crimping in the interior of the pressure screw 65.

[0081] The pressure line 55 is introduced through the base body 62 intothe pressure tube 3 and is mechanically solidly connected to the basebody by the soldered connection 63.

[0082] The pressure line 55 tapers conically on its outer end. Themount, by which the pressure tube 3 is secured in the interior of thepressure screw 65, essentially comprises the crimped-on portion 74 ofthe pressure tube 3 itself. This portion is fastened between a conicaljacket face 75, 78, disposed in the interior of the pressure screw 65,and the conical portion of the pressure line 55, in that the jacket face75, 78 is pressed against the pressure line 55 in the direction towardthe base body by the pressure screw 65. By means of this fastening, theconnection between the pressure tube 3 and the pressure line 55 issealed off.

[0083] The jacket face 75, 78 is for instance, as shown on theright-hand side of FIG. 5, a conical jacket face 78 of the pressurescrew 65 itself, or, as shown on the left-hand side of FIG. 5, a conicaljacket face 75 of an annular cylinder 76 disposed in the pressure screw65.

[0084] In FIGS. 6 and 7, two further embodiments of the connectionbetween the pressure tube 3 and the pressure line 55 are shown. Thepressure measuring cell 5 connected to the pressure tube and thepressure recorder 25 connected to the pressure line 55 are not shownhere, either. Examples of them can be taken identically from FIGS. 1 and2, for instance.

[0085] In the embodiments shown in FIGS. 6 and 7, the connection in eachcase includes a substantially cylindrical base body 77, 79 with acentral axial bore 81, 83 into which the pressure line 55 is introduced.

[0086] In each case a pressure screw 65 is provided, which coaxiallysurrounds the pressure tube 3 and is embodied identically the pressurescrews 65 shown in FIGS. 4 and 5. The pressure screws 65 are union nuts,which take the form of a cylinder closed on one end by the radiallyinward-extending shoulder 67. The cylinders have a female thread, whichis screwed onto a male thread of the base body 77, 79. The pressuretubes 3 are passed through the shoulder 67 into the pressure screw 65and are secured by means of a mount disposed on a side, toward the basebody, of the pressure screw 65.

[0087] The pressure screws 65 are screwed onto the base bodies 77, 79 insuch a way that the pressure tube 3 and the pressure line 55communicate, and sealing of the connection between the pressure tube 3and the pressure line 55 is effected.

[0088] In the exemplary embodiments shown in FIGS. 6 and 7, the sealingis effected by a clamping cone 85, which is disposed on the end in thepressure screw 65 and at the same time forms the mount for the pressuretube 3 passed through the clamping cone 85.

[0089] The clamping cone 85 grips the pressure tube 3 closely and restswith an annular-disklike end face on an inner face of the shoulder 67.It has an outer jacket face 87 that tapers conically in the directiontoward the base body. The base bodies 77, 79 each have a respectiveinner jacket face 89 tapering conically in the direction remote from theclamping cone. The pressure tube 3 is fastened in the clamping cone 85in that the clamping cone 85 is pressed with its conical jacket face bythe pressure screw 65 into the inner jacket face 89 of the respectivebase body 77, 79, this latter jacket face tapering conically toward theclamping cone 85 in the direction remote from the clamping cone.

[0090] The conical outer jacket face 87 of the clamping cone 85 forms amore-acute angle with a longitudinal axis of the pressure tube 3 thandoes the inner jacket face 89 of the respective base body 77, 79. As aresult, some of the force exerted in the axial direction on the clampingcone 85 by the pressure screw 65 is converted into a force that actsinward in the radial direction. This latter force causes a decrease inthe inside diameter of the clamping cone 85 and thus leads to the tight,mechanically solid fastening of the pressure tube 3 in the clamping cone85.

[0091] Once again, the base bodies 77, 79 and the pressure screws 65comprise metal, such as a special steel. The clamping cone 85 preferablyalso comprises a metal. What is suitable is a material, such as copper,that is mechanically softer than the material comprising the base bodies77, 79 and the pressure screws 65.

[0092] In the exemplary embodiment shown in FIG. 6, the pressure line 55is connected mechanically solidly and tightly to the base body 77, forinstance by being soldered into the bore 81.

[0093] In the exemplary embodiment shown in FIG. 7, only one end of thepressure line 55 is introduced into the bore 83, and the pressure line55 is fastened in the same way as the pressure tube 3.

[0094] To that end, an identically shaped second pressure screw 91 isprovided, on an end of the base body 79 facing the pressure screw 67,through which the pressure line 55 is introduced into the bore 83 thatpenetrates the base body 79. The second pressure screw 91 is screwedonto the base body 79. A second clamping cone 93 is disposed on the endin the second pressure screw 91 and has an outer jacket face 95 thattapers conically in the direction toward the base body. The secondclamping cone 93 grips the pressure line 55. This pressure line isfastened in the clamping cone 93, in that the second pressure screw 91presses the second clamping cone 93 with its conical jacket face 95 intoan inner jacket face 97 of the base body 79 that tapers conically,toward the second clamping cone 93, in the direction remote from theclamping cone.

[0095] It is understood that the exemplary embodiments shown in FIGS. 3,4, 5, 6 and 7 can also be embodied as a mirror image instead. Themirror-image form is obtained by simply converting the pressure tubesand pressure lines 55 and the pressure lines 55 into pressure tubes 3.

1. A pressure measuring arrangement, having a pressure measuring cell(5), to which a pressure corresponding to a pressure to be measured isdelivered via a fluid-filled pressure tube (3); at least one pressurerecording unit (25, 45) disposed separately therefrom, on which inoperation a pressure to be measured acts, and which makes a pressurecorresponding to the pressure to be measured available via afluid-filled pressure line (33, 55); and a connection between thepressure tube (3) and the pressure line (33, 55), which connectionincludes: a base body (27, 57, 59, 62, 77, 79), in which at least oneend portion of the pressure line (33, 55) is disposed, a pressure screw(35, 65), through which screw the pressure tube (3) is passed and issecured there by means of a mount disposed on a side of the pressurescrew (35, 65) oriented toward the base body, and which screw has athread by means of which it is screwed onto the base body (27, 57, 59,62, 77, 79), in such a way that the pressure tube (3) and the pressureline (33, 55) communicate, and sealing of the connection between thepressure tube (3) and the pressure line (33, 55) is effective.
 2. Apressure measuring arrangement, having a pressure measuring cell (5), towhich a pressure corresponding to a pressure to be measured is deliveredvia a fluid-filled pressure tube (4); at least one pressure recordingunit (45) disposed separately therefrom, on which in operation apressure to be measured acts, and which makes a pressure correspondingto the pressure to be measured available via a fluid-filled pressureline (34); and a connection between the pressure tube (4) and thepressure line (34), which connection includes: a base body (28), inwhich at least one end portion of the pressure line (34) is disposed, apressure screw (35, 65), through which screw the pressure line (34) ispassed and is secured there by means of a mount disposed on a side ofthe pressure screw (35, 65) oriented toward the base body, and whichscrew has a thread by means of which it is screwed onto the base body(28), in such a way that the pressure tube (4) and the pressure line(34) communicate, and sealing of the connection between the pressuretube (4) and the pressure line (34) is effective.
 3. The pressuremeasuring arrangement of claim 1 or 2, in which the thread is a malethread, which is screwed into a recess (41) in the base body (27, 28,57); the pressure line (33, 55) or the pressure tube (4) leads to therecess (41); the mount (39) is a ring mechanically solidly connected tothe pressure tube (3) or to the pressure line (4), which in the mountedstate rests sealingly, with an end face oriented toward the pressurescrew (35), on an end face of the pressure screw (35) oriented towardthe base body.
 4. The pressure measuring arrangement of claim 3, inwhich the pressure tube (3) or the pressure line (34) tapers conicallyon the outward end, and rests sealingly on a conical inside face of thesame shape in the region of the orifice of the pressure line (33, 55) orof the pressure tube (4).
 5. The pressure measuring arrangement of claim1, in which the pressure screw (65) is a union nut, which takes the formof a cylinder closed on one end by a radially inward-extending shoulder(67); the cylinder has a female thread, which is screwed onto a malethread of the base body (59, 61, 62, 77, 79); and the pressure tube (3)is passed through the shoulder (67) into the pressure screw (67).
 6. Thepressure measuring arrangement of claim 5, in which the pressure line(55) discharges into the base body (59) and is connected tightly andmechanically solidly to it; the pressure tube (3) is connected tightlyand mechanically solidly to an annular disk (69) coaxially surroundingthe pressure tube; an end face of the annular disk (69) rests on anannular-disklike inside face of the shoulder (67); and the annular disk(69) is pressed by the pressure screw (65) in the direction toward thebase body.
 7. The pressure measuring arrangement of claim 6, in whichbetween the annular disk (69) and the base body (59), a sealing element(73) annularly surrounding the pressure tube (3) is provided, by which ahollow chamber, defined by the annular disk (69), the sealing element(73), and the base body (59), and surrounding the pressure tube (3) issealed off.
 8. The pressure measuring arrangement of claim 5, in whichthe pressure tube (3) is widened by crimping in the interior of thepressure screw (65); the pressure line (55) is introduced into thepressure tube (3); the pressure line (55) is passed through the basebody (62) and mechanically solidly connected to it; the pressure line(55) tapers conically on the outward end; and a crimped-on end portion(74) of the pressure tube (3) is fastened sealingly between a conicaljacket face (75, 78), disposed in the interior of the pressure screw(65), and the conical portion of the pressure line (55), in that thejacket face (75, 78) is pressed against the pressure line (55) by thepressure screw (65) in the direction toward the base body.
 9. Thepressure measuring arrangement of claim 5, in which a clamping cone (85)is disposed on the end in the pressure screw (65), which clamping conehas an outer jacket face (87) that tapers conically in the directiontoward the base body, which jacket face grips the pressure tube (3) andin which the pressure tube (3) is fastened, in that the clamping cone(85) is pressed inward with its conical jacket face by the pressurescrew (65) into an inner jacket face (89) of the base body (77, 79) thatis oriented toward the clamping cone (85) and tapers conically in thedirection remote from the clamping cone.
 10. The pressure measuringarrangement of claim 9, in which on an end of the base body (79) facingthe pressure screw (65), a second pressure screw (91) of identical formis provided, through the pressure line (55) is introduced into a bore(83) penetrating the base body (79), in which bore a second clampingcone (93) is disposed on the end, which clamping cone has an outerjacket face (95) tapering conically in the direction toward the basebody, which jacket face grips the pressure line (55) and in which thepressure line (55) is fastened, in that the second clamping cone (93) ispressed inward with its conical jacket face (95) by the second pressurescrew (93) into an inner jacket face (97) of the base body (79) orientedtoward the second clamping cone (93) and tapering conically in thedirection remote from the clamping cone.